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A new type high frequency transformer
IEEE Transactions on Magnetics, 1991In order to realize small power supplies, the authors propose a type of coreless high-frequency transformer. This transformer is composed of simple twisted coils and its operating principle is based on the skin effect of current carrying conductors. Approximate analysis based on the symmetrical current distributions in each of the coil axes has been ...
S. Hayano +3 more
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A high frequency transformer model for the EMTP
IEEE Transactions on Power Delivery, 1993A model to simulate the high-frequency behavior of a power transformer is presented. This model is based on the frequency characteristics of the transformer admittance matrix between its terminals over a given range of frequencies. The transformer admittance characteristics can be obtained from measurements or from detailed internal models based on the
A. Morched, L. Marti, J. Ottevangers
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High-frequency investigation of planar transformers
2014 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2014Planar transformers are a novel type of devices used in integrated power systems. Having many advantages compared to classic wire wound technology; it's used to minimize size and weight and to increase their ability to withstand mechanical vibrations.
Aymen Ammouri +3 more
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High-Voltage, High-Frequency Transformer Design
2012Conversion of AC mains voltages to a high-voltage (>10 kV), high-power (>10 kW) DC level is a key area of technology which is a requirement in many industrial processes, for example, in particulate emission control using electrostatic precipitators. In the majority of cases, this high-voltage DC requirement is achieved with a singlephase AC regulator ...
Paul Lefley, Philip Devine
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High–Frequency Transformation of Penicillium Chrysogenum
Nature Biotechnology, 1987We report high–frequency transformation of penicillin–producing strains of Penicillium chrysogenum using plasmid vectors carrying the pyr4 gene of Neurospora crassa. Transformation to stable uracil independence is associated with acquisition of transforming DNA in high molecular forms that are not simple multimers of the vector.
J. M. Cantoral +4 more
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Propagation of high frequency overvoltages in transformers
2014 ICHVE International Conference on High Voltage Engineering and Application, 2014In modern grids and networks more and more switching and reconfiguration operations are present. In addition external stresses like lightning may cause overvoltages. Thus, such transients may subject the electric insulation system of power equipment.
M. Florkowski +3 more
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High-Frequency Impedance Transformations
2010Active devices such as transistors or Op-Amps have bandwidth limitations that can result in instability or undesirable dynamic response in feedback circuits. As gain decreases with frequency, feedback-amplifier port-resistance values also change and effectively become reactive. These bandwidth-related reactances can resonate with other circuit elements.
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Analysis of high-frequency resistance in transformers
20th Annual IEEE Power Electronics Specialists Conference, 2003An accurate, analytical method is proposed for calculating the lead and winding high-frequency resistance of complex transformer constructions. High-frequency resistance is derived from the resulting matrix system equations, common to the leads and windings. The effect of eddy currents in the leads is confirmed by theoretical results.
K. Sakakibara, N. Murakami
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Modeling of high-frequency micro-transformers
IEEE Transactions on Magnetics, 2004A dynamic model has been developed to predict the efficiency of a micro-transformer, operating at 5 MHz. The model includes a core hysteresis model, core eddy current model and winding copper loss model. Measurements and finite element analysis were carried out in order to validate the model.
null Ningning Wang +5 more
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High-frequency planar power transformers
IEEE Transactions on Power Electronics, 1992High-frequency transformer design using the transmission line transformer (TLT) is described. Utilizing transmission line circuit theory, the characteristics of the TLT for different turn ratios are given, and its advantages, including its wideband nature, are discussed. TLT prototypes with turn ratios of 2:1, 3:1, and 5:1 were designed and fabricated.
M.A. Morrill, V.A. Caliskan, C.Q. Lee
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